What is the equivalent capacitance between points a and b? All capacitors are 2.5 μF.
A) 1.42 µF
B) 0.36 µF
C) 1.5 µF
D) 0.67 µF
E) 0.27 µF

Question

What is the equivalent capacitance between points a and b? All capacitors are 2.5 μF. 
A) 1.42 µF 
B) 0.36 µF 
C) 1.5 µF 
D) 0.67 µF 
E) ​0.27 µF

Quizplus · Accepted Answer

The capacitors are in parallel and series combination. Capacitors A and B are in parallel so their equivalent capacitance is:

C_AB = C_A + C_B = 2.5 µF + 2.5 µF = 5 µF

Capacitor C is in series with the parallel combination of capacitors A and B, so the total equivalent capacitance is:

C_eq = (C_AB * C_C) / (C_AB + C_C) = (5 µF * 2.5 µF) / (5 µF + 2.5 µF) = 1.67 µF

Rounding off to two significant figures, we have:

C_eq ≈ 1.5 µF

Therefore, the best choice is C) 1.5 µF.

What Is the Equivalent Capacitance Between Points a and B